How to Prepare for the Test

You will need to have a full bladder to get the best ultrasound image. You may be asked to drink 2 to 3 glasses of liquid an hour before the test. Do not urinate before the procedure.

How the Test will Feel

There may be some discomfort from pressure on the full bladder. The conducting gel may feel slightly cold and wet. You will not feel the ultrasound waves.

Why the Test is Performed

An ultrasound may be done to determine if there is a problem with the pregnancy, how far along the pregnancy is, or to take measurements and screen for potential problems.

Talk to your health care provider to determine the most appropriate scanning schedule for you.

A pregnancy ultrasound may be done during the first 12 weeks of pregnancy to:

Confirm a normal pregnancy

Determine the baby's age

Look for problems, such as ectopic pregnancies or the chances for a miscarriage

Determine the baby's heart rate

Look for multiple pregnancies (twins, triplets, etc.)

Identify problems of the placenta, uterus, cervix, and ovaries

Look for findings that might indicate an increased risk for Down syndrome

A pregnancy ultrasound may also be done in the second and third trimesters to:

Determine the baby's age, growth, position, and sometimes gender

Identify any problems with how the fetus is developing

Look for twins, triplets, etc.

Look at the placenta, amniotic fluid, and pelvis

Some centers are now performing a pregnancy ultrasound around 9 - 13 weeks of pregnancy to look for signs of Down syndrome or other problems in the developing baby. This test is often combined with blood tests to improve the accuracy of results.

How many ultrasounds you will need depends on whether a previous scan or blood test has detected problems that require follow-up testing.